Build and deploy a Rails app on Fly.io using Nix.
Roughly, we want to do as much of this as possible, in order:
- Be able to specify Ruby minor versions (patch versions require more work)
- Cache gems between builds and layer them intelligently in the Docker image
- Use Nixpkgs, if possible, to define build dependencies for gems
rails assets:precompile
should be run during the build, its output being cached and captured in the resulting image- The result of the build should be a Docker image ready to be pushed to Fly
Bundix supports gem setup from nixpkgs